Bottom Line:
This comparison serves as an indicator of what sorts of changes might exist between modern humans living in Western culture compared to our hunter-gatherer ancestors.However, immunological experiments on wild-caught animals are difficult and potentially confounded by increased levels of stress in the captive animals.However, animals housed in the enriched biodiversity setting demonstrated an increased mean humoral response to T-independent and T-dependent antigens and increased levels of "natural" antibodies directed at a xenogeneic protein and at an autologous tissue extract that were not used as immunogens.

Affiliation: Department of Surgery, Duke University Medical Center, Durham, NC, United States of America.

ABSTRACTPrevious studies have compared the immune systems of wild and of laboratory rodents in an effort to determine how laboratory rodents differ from their naturally occurring relatives. This comparison serves as an indicator of what sorts of changes might exist between modern humans living in Western culture compared to our hunter-gatherer ancestors. However, immunological experiments on wild-caught animals are difficult and potentially confounded by increased levels of stress in the captive animals. In this study, the humoral immune responses of laboratory rats in a traditional laboratory environment and in an environment with enriched biodiversity were examined following immunization with a panel of antigens. Biodiversity enrichment included colonization of the laboratory animals with helminths and co-housing the laboratory animals with wild-caught rats. Increased biodiversity did not apparently affect the IgE response to peanut antigens following immunization with those antigens. However, animals housed in the enriched biodiversity setting demonstrated an increased mean humoral response to T-independent and T-dependent antigens and increased levels of "natural" antibodies directed at a xenogeneic protein and at an autologous tissue extract that were not used as immunogens.

pone.0120255.g001: Body weights of biome depleted and biome enriched rats at (A) 4 days old, (B) 23 days old, and (C) 63 days old.The mean ± the standard error is indicated by the horizontal lines. No statistical significance (NS) was observed with comparing data from biome depleted and biome enriched animals using a t-test.

Mentions:
All F1 rats exhibited normal respiration and social interactions. In addition, body weights of all F1 rats were measured when the rats were 4 days old, 23 days old and again at 63 days old to gauge the effect of biome depletion and enrichment on the overall health of the animals. As shown in Fig. 1, no significant difference was found between the mean body weights of the biome depleted and the biome enriched animals. However, at 23 days of age, two of the biome depleted animals showed a 40% greater body mass than average for either group. Two biome depleted animals of unusually high weight were also present at day 63, although it is unknown if these were the same two animals, and their weights were not as high above the mean at day 63 as on day 23.

pone.0120255.g001: Body weights of biome depleted and biome enriched rats at (A) 4 days old, (B) 23 days old, and (C) 63 days old.The mean ± the standard error is indicated by the horizontal lines. No statistical significance (NS) was observed with comparing data from biome depleted and biome enriched animals using a t-test.

Mentions:
All F1 rats exhibited normal respiration and social interactions. In addition, body weights of all F1 rats were measured when the rats were 4 days old, 23 days old and again at 63 days old to gauge the effect of biome depletion and enrichment on the overall health of the animals. As shown in Fig. 1, no significant difference was found between the mean body weights of the biome depleted and the biome enriched animals. However, at 23 days of age, two of the biome depleted animals showed a 40% greater body mass than average for either group. Two biome depleted animals of unusually high weight were also present at day 63, although it is unknown if these were the same two animals, and their weights were not as high above the mean at day 63 as on day 23.

Bottom Line:
This comparison serves as an indicator of what sorts of changes might exist between modern humans living in Western culture compared to our hunter-gatherer ancestors.However, immunological experiments on wild-caught animals are difficult and potentially confounded by increased levels of stress in the captive animals.However, animals housed in the enriched biodiversity setting demonstrated an increased mean humoral response to T-independent and T-dependent antigens and increased levels of "natural" antibodies directed at a xenogeneic protein and at an autologous tissue extract that were not used as immunogens.

Affiliation:
Department of Surgery, Duke University Medical Center, Durham, NC, United States of America.

ABSTRACTPrevious studies have compared the immune systems of wild and of laboratory rodents in an effort to determine how laboratory rodents differ from their naturally occurring relatives. This comparison serves as an indicator of what sorts of changes might exist between modern humans living in Western culture compared to our hunter-gatherer ancestors. However, immunological experiments on wild-caught animals are difficult and potentially confounded by increased levels of stress in the captive animals. In this study, the humoral immune responses of laboratory rats in a traditional laboratory environment and in an environment with enriched biodiversity were examined following immunization with a panel of antigens. Biodiversity enrichment included colonization of the laboratory animals with helminths and co-housing the laboratory animals with wild-caught rats. Increased biodiversity did not apparently affect the IgE response to peanut antigens following immunization with those antigens. However, animals housed in the enriched biodiversity setting demonstrated an increased mean humoral response to T-independent and T-dependent antigens and increased levels of "natural" antibodies directed at a xenogeneic protein and at an autologous tissue extract that were not used as immunogens.